Prognostic implication of staging of seminal vesicle invasion in patients with prostatic adenocarcinoma after prostatectomy

Objectives To evaluate whether the extent of seminal vesicle invasion of prostatic adenocarcinoma can stratify the risk of biochemical recurrence after radical prostatectomy. Methods We carried out radical prostatectomy for 1309 patients with prostatic adenocarcinoma between 2006 and 2019; 135 (10.3%) patients had seminal vesicle invasion. After excluding patients with neo-/adjuvant therapy, we reviewed 105 patients. We analyzed the correlation of the extent of seminal vesicle invasion and biochemical recurrence-free survival after prostatectomy and adjusted by various clinicopathological factors in multivariate analyses. Seminal vesicle invasion was stratified into three groups; the proximal part from the base was defined as level 1, followed by level 2 and the distal part as level 3. Results Among the 105 patients, 30 (29%), 54 (51%) and 21 patients (20%) had seminal vesicle invasion at levels 1, 2 and 3, respectively. Median times to biochemical recurrence were 110, 67 and 12 months in patients with levels 1, 2 and 3, respectively (P = 0.002). The extent of seminal vesicle invasion was the independent risk factor for biochemical recurrence in univariate (level 3 vs 1, P = 0.001; level 3 vs 2, P = 0.015) and multivariate analyses (level 3 vs 1, P = 0.025; level 3 vs 2, P = 0.030). Conclusions The extent of seminal vesicle invasion might be a significant predictor of biochemical recurrence in prostate cancer patients undergoing radical prostatectomy.